The present invention relates to a communication system.
In recent years, fast popularization of smartphones, tablet terminals, and the like has resulted in a rapid increase in mobile traffic in the network. Responding to this situation, in radio network that forwards the mobile traffic, a high-speed radio communication such as LTE (Long Term Evolution) and WiMAX have started to be popularized in place of 3G. In the case of using such a high-speed radio communication, users can enjoy a comfortable communication like the conventional cable communication, in the environment in which wireless link errors (packet losses) are unlikely to occur, or the environment in which accesses are not congested.
On the other hand, in the case where a radio network is in the environment in which wireless link errors (packet losses) are likely to occur, or the environment in which accesses are congested, even when the high-speed radio communication is used, transmission throughput reduces in the radio network, and Quality of Experience (QoE) is lowered, because of characteristics of the generally-used TCP/IP (Transmission Control Protocol/Internet Protocol) communication.
In order to improve the quality of experience, it is important to secure a communication band in the radio network, and establish a state that the secured communication band can be utilized to an upper limit even in the congestion status. In the light of this importance, conventionally, there has been proposed a task of providing a radio resource allocation method by which a service quality can be controlled according to a characteristic of dataflow and by which it is possible to improve fairness of a user quality of experience among users who utilize the same type of application services (see JP2012-191372A, for example).
JP 2012-191372A discloses that a network including base station devices includes: a required QoE determination part for estimating required QoE to be requested by users; a data flow characteristic analysis part for analyzing the characteristics of data flows; a target Quality of Service (QoS) determination part for determining target QoS, based on the required QoE and the data flow characteristics; and a radio resource allocation part for determining radio resource amounts, based on the target QoS.
JP2012-175561A discloses a problem of improving communication throughput according to environment in a transmission control method. It further discloses a transmission control method, in which each of a transmission source and transmission destination communication devices has a transmission control protocol including a plurality of congestion control functions corresponding respectively to a plurality of congestion control systems, and communicates mutually by using the transmission control protocol, has a step of forwarding at least one of a plurality of parameters showing an action state of a first congestion control function retained by the transmission control protocol to a parameter showing an action state of a second congestion control function when the transmission source and transmission destination communication devices switch from the first congestion control function to the second congestion control function.